Note: Descriptions are shown in the official language in which they were submitted.
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APPLICATION DEVICE AND METHOD FOR PRODUCING AN APPLICATION DEVICE
Description
[0002] The invention relates to an application device for applying a
viscous material to a
substrate. The invention also relates to a method for producing such an
application device.
[0003] Such application devices are known in the prior art as application
tools and are used,
for example, in industry, in crafts or in the DIY area. For example, such
application devices can be
used to dispense sealants to close joints between components in the sanitary
area. Alternatively,
adhesives or other viscous materials can be applied using such application
devices.
[0004] An application device is known from W02016/166237, which has a
container for
receiving a sealant and an applicator that can be placed on an opening of the
container and latched
to the container. The applicator has a dispensing opening for dispensing the
sealant from the
container onto a substrate and is also designed in such a manner that
immediately after dispensing,
on the one hand, the dispensed sealant is smoothed and, on the other hand,
adjacent surface regions
of the substrate are freed from excess sealant. In other words, the applicator
is used for both
dispensing and forming the sealant, as well as for subsequent cleaning of
adjacent regions of the
substrate. The sealant is dispensed from the container of the application
device by squeezing the
container wall by a user. A front and a rear actuating surface of the
container are moved toward one
another in such a manner as to cause a reduction in the internal volume of the
container, thereby
forcing the sealant into the applicator and dispensing it through the
dispensing opening thereof. For
this purpose, the actuating surfaces can be designed to be flexible or thin-
walled in regions to allow
and facilitate deformation of the container wall.
[0005] Such an application device has several disadvantages. Since many
viscous materials
have thixotropic behavior, it is usually necessary to agitate the application
device before use to
improve the flowability of the material and to convey it to the dispensing
opening. Particularly for
applications on vertically oriented substrates, this process may have to be
repeated several times
during the application to ensure the availability of the product at the
dispensing opening. However,
shaking introduces air into the material, which is disadvantageous for uniform
and bubble-free
discharge of the material. As soon as the pressure effect on the container
subsides and the container
wall returns to its original shape due to the restoring forces acting, a
certain amount of viscous
material may be drawn back into the application device due to the existing
vacuum. In addition, air
in particular is drawn into the container from the outside. This air escapes
in an uncontrolled manner
during subsequent dispensing procedures and/or may become trapped in the
applied material. Such
air pockets can impair the function of the applied material, for example a
sealing function or an
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adhesive function, and the durability of the product is reduced by the
penetration of air into the
container.
[0006] Finally, due to the flexible but still comparatively solid
material of the container wall,
residual emptying of the container is hardly possible, i.e. considerable
amounts of viscous material
always remain in the container, which can no longer be discharged by
compressing the container
wall.
[0007] An application device is known from DE 20 2015 106 902 U1, which
has a receiving
container for a paste-like composition, a cap with a pouring spout, and a
deformable wrapping
surrounding the receiving container. The wrapping has a bellows-type fold,
which promotes
squeezing of the wrapping to discharge the pasty mass from the receiving
container. This can result
in improved residual drainage, but the problem of air intake and air pockets
exists in equal measure
here.
[0008] It is therefore the object of the present invention to provide an
application device which
overcomes the disadvantages of the prior art and which enables a viscous
material to be dispensed
from a container onto a substrate in a uniform and more complete manner in a
simple manner. It is
a further object of the invention to provide a method for producing such an
application device.
[0009] These objects are solved by an application device having the
features of claim 1 and by
a method having the features of claim 10.
[0010] In accordance with claim 1, the invention proposes an application
device for applying a
viscous material to a substrate, comprising an inner casing having a
dispensing opening for receiving
the viscous material, an outer casing surrounding the inner casing and having
a substantially hollow
cylindrical neck region of an inner diameter D1 and an opening formed in the
neck region, and an
applicator connected to the outer casing, wherein the viscous material can be
delivered from the
inner casing into the applicator by pressure on the outer casing and applied
to a substrate by the
applicator. The application device according to the invention is characterized
in that it comprises a
ventilation device comprising an insert which is connected to the inner casing
in an airtight manner
in the region of the dispensing opening, which insert is substantially
designed in the shape of a hollow
cylinder and has an outer diameter D2, wherein the outer diameter D2 of the
insert is smaller than
the inner diameter D1 of the neck region of the outer casing, and wherein the
insert has latching
means on its outer side by means of which it is latched in the insert position
within the neck region
of the outer casing, in which insert position, due to the different diameters
D1 and D2, an annular
gap is designed between the insert and the neck region of the outer casing,
through which air can
flow from the outside into the intermediate space between the outer casing and
the inner container
and vice versa, and wherein furthermore the connection between the applicator
and the outer casing
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is designed to be air-permeable and the applicator comprises a sealing means
by which, in the use
position of the applicator, an airtight and leak-proof sealing of the inner
volume of the inner container
with respect to the intermediate space between the outer casing and the inner
container is provided.
[0011] In other words, the invention proposes to incorporate a
ventilation device into the
application device in such a manner that when the outer casing is compressed,
air located between
the outer casing and the inner container first exits through the annular gap
between the neck region
of the outer casing and the insert of the inner container and exits through
the non-air-tight connection
region between the applicator and the outer casing, such as a threaded
connection. Pressure on the
outer casing is transmitted to the inner casing, causing viscous material to
be conveyed from the
inner casing into the applicator and dispensed from the applicator onto a
substrate. As soon as the
pressure on the outer casing is released, air is drawn in again from outside
through the connection
region between the applicator and the outer casing into the intermediate space
between the inner
container and the outer casing in order to relieve the pressure built up here
and return the outer
casing to its original shape. At the same time, however, no air enters the
inner casing storing the
viscous material, since this is sealed off from the intermediate space between
the outer casing and
the inner casing by a sealant arranged in the applicator, for example a
sealing ring, according to the
invention. The outer casing thus resumes its original shape after each
application procedure due to
the inflow of air, while the inner container is further compressed and
irreversibly deformed with each
application procedure.
[0012] The integrated ventilation device prevents air from being drawn
into the inner container
storing the viscous material during metering and subsequent resetting of the
outer casing. This
eliminates the need to shake or "spike" the application device prior to use
and ensures an air bubble-
free application of the viscous material to a substrate. Since the inner
container is further deformed
with each application procedure and this deformation is not reversible, the
viscous material cannot
run back into regions of the inner container from which it would first have to
be moved back towards
the dispensing opening. Instead, the viscous material is always immediately
available in any
orientation of the application device, for example even in overhead
applications, and can be
dispensed reliably and without bubbles. This results in significantly improved
residual emptying. The
external appearance of the application device is thereby consistently
attractive to a user, since the
outer casing always returns to its original shape, while the increasingly
deformed inner container is
not visible to the user. In addition, the lack of air intake into the inner
container also extends the
durability of the viscous material.
[0013] The applicator acts as a metering and molding system and is
connected to the outer
casing. To connect the applicator and outer casing, the neck region of the
outer casing may have an
external thread and the applicator may have a corresponding internal thread.
The threaded
connection can be designed as a right-hand thread, but it can in particular
also be designed as a left-
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hand thread to counteract accidental unscrewing of the applicator from the
outer casing by a user.
In any case, the threaded connection is designed to be permeable to air, thus
allowing air to flow
through the thread into the intermediate space between the inner container and
outer casing, and
vice versa. A sealant contained in the applicator seals the inner volume of
the inner container from
these air flows.
[0014] The application device according to the invention is equally
suitable for the initial
application of viscous material, for example sealing material, to a substrate,
as well as for the
subsequent application of material to an existing material layer that may be
in need of repair.
[0015] In accordance with an embodiment of the invention, the annular gap
designed between
the insert of the inner container and the neck region of the outer casing has
a gap width of 0.4 to 1
mm. This gap width results from half the difference between the inner diameter
D1 of the neck region
of the outer casing and the outer diameter D2 of the insert. Such a gap width
ensures that air can
quickly escape to the outside from the intermediate space between the outer
casing and the inner
container when the outer casing is compressed, and that air can just as
quickly flow back into this
intermediate space from the outside when the pressure on the outer casing is
released. In this case,
air is drawn into the intermediate space much faster than any slight
retraction of the viscous material
from the dispensing opening of the applicator, such that a pressure
equilibrium has already been
restored before the viscous material possibly retracts slightly from the
dispensing opening of the
applicator. In this manner, air can be prevented from entering the inner
container.
[0016] The outer casing may have a bottle-like shape. In this regard, the
cross-section of the
outer casing may be substantially rectangular, in such a manner that a front
and a rear actuating
surface are designed to be moved toward one another for transmitting pressure
to the inner
container.
[0017] According to an embodiment of the invention, the outer casing has
a lamella fold by
which compression of the outer casing is facilitated. A bellows-type lamella
fold promotes
compression of the outer casing to discharge the viscous material from the
inner container. In
accordance with a preferred embodiment, the lamella fold is thereby designed
in such a manner that
compression of the outer casing occurs substantially in a direction
perpendicular to a main flow
direction of the viscous material. A main flow direction of the material is
given by a direction from a
rear end of the inner container towards the discharge opening located at an
opposite end of the inner
container. By folding regions of the outer casing in a direction parallel to
this main flow direction, the
outer casing can be easily compressed in a direction perpendicular to the main
flow direction. In this
manner, one-handed operation of the application device according to the
invention is possible by a
user holding the outer casing between the thumb and at least one further
finger of the same hand
and, by moving the thumb and the at least one further finger towards one
another, compressing the
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outer casing, favored by the lamella fold, without great effort. The pressure
exerted on the outer
casing is transmitted to the inner container and the viscous material is
conveyed into the applicator
and dispensed from it onto a substrate. The good compressibility of the outer
casing promotes good
residual drainability.
[0018] The number of folds or lamellae can vary in principle, wherein a
larger number of
lamellae facilitates compression of the outer casing, but at the same time is
associated with reduced
strength and stability of the outer casing. In this respect, a compromise must
be found between good
compressibility on the one hand and sufficient stability of the outer casing
on the other. In general,
such a compromise is given with a number of 3 to 7 lamellas. The opening angle
between two
adjacent lamellas can be about 300-550
.
[0019] In accordance with one embodiment of the invention, the inner
container is designed as
a film bag. A film bag is generally highly flexible and thus readily
deformable, such that the pressure
exerted over the outer casing can be easily and efficiently transmitted to the
film bag and the viscous
material stored therein. For example, the inner container may be designed from
an aluminum-based
film. The film material may be a laminate comprising at least one aluminum
layer. Such materials
also have sufficient stability and strength to prevent the film bag from
tearing open and the viscous
material from accidentally escaping into the intermediate space between the
inner container and the
outer casing, even when forces are applied, such as when the application
device falls to the ground
from a certain height. This is all the more important because a user would not
be immediately aware
of a leak in the film bag due to the outer casing surrounding the film bag.
Finally, an aluminum
laminate has the advantage of being largely impervious to moisture. In this
manner, water can be
prevented from diffusing from the viscous material through the bag wall and
the viscous material can
be prevented from curing while still in the application device. This gives the
product a significantly
improved storability. An exemplary laminate is constructed as a four-layer
composite consisting of a
PET layer, an aluminum layer, an OPA layer and a PE layer.
[0020] An embodiment of the invention provides that the inner container
is connected to the
insert by welding, wherein the welded connection has a pressure tightness up
to at least 1,5 bar. The
connection between the application device and the inner container is thus
designed to withstand
forces such as those that occur when the application device falls to the
ground from a certain height,
thus preventing the application device from detaching from the inner container
and the viscous
material from escaping into the intermediate space between the inner container
and the outer casing.
The insert itself may be produced from a thermoplastic, for example, using an
injection molding
process.
[0021] In an embodiment of the invention, the applicator comprises a main
body and means
for smoothing the applied viscous material and/or means for cleaning adjacent
substrate regions.
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For this purpose, a delta-shaped wing can be formed on the main body of the
applicator, the outer
edges of which serve for smoothing the applied material and cleaning adjacent
substrate regions.
The applicator may also comprise a substantially rectangularly designed blade
having at least one
smoothing or cleaning edge. In this regard, it may be provided that the
applicator has at least two
materials of different stiffness, wherein the main body is made of a stiffer
material than the means
for smoothing and/or the means for cleaning. For example, the outer edges of
the blade used for
smoothing and/or cleaning can be made of a pliable material, while the main
body of the applicator
is made of a stiff material, such as a thermoplastic elastomer. With an
applicator designed in this
manner, the viscous material can be dispensed and formed in one operation by
applying pressure to
the outer casing and simultaneously pulling the application device over the
substrate, and excess
material can be pulled off the substrate and collected.
[0022] The invention also relates to a method for producing an
application device according to
one of claims 1 to 9, comprising the following steps:
- providing an inner container and an insert connected to the inner
container, an outer casing
having a neck region and an opening, and an applicator;
- U-shaped folding of the inner container by directly superimposing a left
flank of the inner
container and a right flank of the inner container;
- inserting the U-shaped folded inner container through the opening in the
outer casing;
- latching the insert of the inner container to the neck region of the
outer casing, forming an
annular gap between the insert of the inner container and the neck region of
the outer casing;
- filling the inner container with the viscous material;
- applying the applicator to the outer casing and joining the applicator
and the outer casing,
wherein the joining of the applicator and the outer casing is air-permeable
while the applicator seals
the intermediate space between the outer casing and the inner container from
the inner volume of
the inner container;
- if necessary, placing a protective cap on the applicator and latching the
protective cap to the
outer casing.
[0023] In order to insert the inner container into the outer casing, it
is necessary to fold the
inner container. By filling the inner container with the viscous material, the
inner container is finally
unfolded again inside the outer casing. Essential to the method according to
the invention is the U-
shaped folding of the inner container, for example of a film bag, in which a
right flank of the inner
container and a left flank of the inner container are placed directly one
above the other. This
distinguishes the U-shaped fold from a so-called Z-shaped fold, in which one
lateral flank of the inner
container is folded over to the front, while the other lateral flank is folded
over to the rear. Compared
to a Z-shaped fold, a U-shaped fold has the advantage of a significantly
improved and more reliable
unfolding of the inner container when filled with the viscous material, thus
enabling a more uniform
and complete filling of the inner container.
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[0024] In accordance with an embodiment of the method, the outer casing
of the application
device can be manufactured from a thermoplastic elastomer in an injection blow
molding process. A
combined injection blow molding process is particularly suitable for forming
an outer casing with a
lamella fold.
[0025] In the following, the invention is explained in more detail by
means of embodiment
examples and with reference to the attached figures. In the drawings:
Figure 1: shows an embodiment of an application device according to the
invention in a
perspective view;
Figure 2: shows the outer casing of the application device of Figure 1;
Figure 3: shows a side view of the outer casing shown in Figure 2;
Figure 4: shows an inner container of the application device with an
insert;
Figure 5: shows the inner container of Figure 4 folded in a U-shape;
Figure 6: shows a view of the inner container folded in a U-shape from
above;
Figure 7: shows the inner container of Figure 5 in an already partially
unfolded state;
Figure 8: shows an example of an insert in an oblique view from below;
Figure 9: shows a schematic diagram of the connection region of the
applicator, insert and
outer casing;
Figure 10: shows an alternative embodiment of the applicator in a
perspective view;
Figure 11: shows a schematic sectional view of the insert latched in the
neck region of the outer
casing, forming an annular gap.
[0026] Figure 1 shows an application device, designated 1 in its
entirety, for applying a viscous
material to a substrate. The application device 1 comprises an outer casing 2
and an inner container
3, which is not visible in the illustration of Figure 1, is arranged inside
the outer casing 2 and stores
the viscous material, for example a sealant. The inner container 3 will be
explained in more detail
later in connection with Figures 4-7.
[0027] Furthermore, the application device 1 comprises an applicator 4,
which is connected to
the outer casing 2 via a threaded connection. The threaded connection between
applicator 4 and
outer casing 2 is designed to be air-permeable. An external pressure exerted
on the outer casing 2
is transmitted to the inner container 3, causing the viscous material to be
conveyed from the inner
container 3 into the applicator 4 and then to be applied to a substrate. For
this purpose, the applicator
4 has a dispensing opening 5 through which the viscous material can exit the
application device 1.
[0028] Figures 2 and 3 show two views of the outer casing 2 of the
application device 1 of
Figure 1. The outer casing 2 comprises a neck region 6 having an opening 7,
wherein the neck region
6 is substantially designed as a hollow cylinder and has an inner diameter D1.
The neck region 6 is
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provided with an external thread 8, which serves to screw the outer casing 2
to the applicator 4 of
the application device 1. The external thread 8 is designed as a left-hand
thread.
[0029] The outer casing 2 has a lamella fold 9 in the manner of a
bellows, wherein the lamellae
extend circumferentially, starting from a region below the neck region 6 of
the outer casing 2, over
the left side 11 of the outer casing 2, over its underside 12 and over the
right side 13, in turn up to
the neck region 6. The lamella fold 9 facilitates the compression of the outer
casing 2. For this
purpose, a user can grasp the outer casing 2 with one hand between the thumb
and at least one
other finger and apply pressure to the two opposing actuating surfaces 14 and
15 in such a manner
that the two actuating surfaces 14 and 15 are moved towards one another.
[0030] In this regard, the lamella fold 9 is designed in such a manner
that compression of the
outer casing 2 occurs substantially in a direction perpendicular to a main
flow direction of the viscous
material within the application device 1. A main flow direction of the viscous
material is shown in
Figures 1 and 3 by the arrow 16 and extends from the bottom 12 of the outer
casing 2 towards the
applicator 4 and the opening 7, respectively. In Figure 3, the perpendicular
direction in which the
compression of the outer casing 2 takes place is also indicated by the arrow
17. The embodiment
shown has five lamellas, wherein the opening angle a between two adjacent
lamellas is about 47 .
[0031] Figure 4 shows an inner container 3 of the application device 2.
The inner container 3
is designed as a film bag made of an aluminum laminate with a film thickness
of about 100 pm by
edge sealing. The inner container 3 is used to store the viscous material and
has a dispensing
opening 18. In the region of the dispensing opening 18, an insert 19 is
connected to the inner
container 3 in an airtight manner by welding. The insert 19 is substantially
designed in the shape of
a hollow cylinder, which can be seen more clearly in Figure 6 and in Figure
11. The outer diameter
D2 of insert 19 is smaller than the inner diameter D1 of neck region 6 of
outer casing 2, see also
Figure 11. The insert 19 is part of a ventilation device, which will be
explained in more detail below.
[0032] In the application device 1 of Figure 1, the inner container 3 is
arranged inside the outer
casing 2. For insertion into the outer casing 2, the inner container 3 is
folded in a U-shape, which can
be seen in Figures 5 and 6. For this purpose, the right flank 20 is first
folded onto the central region
of the inner container 3 and then the left flank 21 of the inner container 3
is placed directly over it.
Figure 6 shows a top view of the arrangement of the flanks 20 and 21 of the
inner container 3 in the
U-shaped folded state. In this state, the inner container 3 can be inserted
through the opening 7 into
the inner region of the outer casing 2. Subsequent filling of the inner
container 3 with the viscous
material through the opening 18 causes the inner container 3 to gradually
unfold, wherein an upper
region of the inner container 3 unfolds first, which is indicated in Figure 7,
before the lower region of
the inner container 3 also unfolds completely upon further filling. Compared
to other types of folding,
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the U-shaped folding results in a particularly reliable unfolding of the inner
container 3, enabling a
more uniform and complete filling with viscous material.
[0033] The inner container 3 inserted into the outer casing 2 is
connected to the outer casing
2 by a latching mechanism. For this purpose, the insert 19 connected to the
inner container 2 has
latching means 22 on its outer side, cf. also Figure 8, which, in the
insertion position of the inner
container 3 in the outer casing 2, latch with corresponding latching means on
the inner side of the
neck region 6 of the outer casing 2. Due to the difference between the outer
diameter D2 of the insert
19 and the inner diameter D1 of the neck region 6, an annular gap is designed
between the insert 19
and the neck region 6 of the outer casing 2 in the insert position of the
insert 19, see Figure 11.
Figure 11 shows a top view of a section through the insert 19 along the line A-
B indicated in Figure
5, wherein the insert 19 is inserted into the neck region 6 of the outer
casing 2. The annular gap is
shown here by a shaded region, though not to scale. Air can flow through this
annular gap into the
intermediate space between the outer casing 2 and the inner container 3 and
vice versa. In the
embodiment shown, the diameter D1 is about 193 mm and the diameter D2 is about
17.8 mm. The
annular gap thus has a gap width of about 0/5 mm.
[0034] Figure 9 shows a section of the connection region of applicator 4,
insert 19 and neck
region 6 of outer casing 2 in schematic, partially cutaway view. The threaded
connection between
the applicator 4 and the neck region 6 of the outer casing 2 is permeable to
air, allowing air to flow
into and through the threaded connection region from the outside in the
direction indicated by the
arrow 23, and finally to flow into the intermediate space between the inner
container 3 and the outer
casing 2 through the annular gap between the insert 19 and the neck region 6
of the outer casing 2
in the region indicated by the arrow 24. At the same time, the applicator 4
has a sealing means 25
by which the inner volume of the inner container 3, which is accessible via
the dispensing opening
18, is sealed with respect to the intermediate space between the outer casing
2 and the inner
container 3. In other words, air can flow into the intermediate space between
outer casing 2 and inner
container 3, but this air cannot flow into inner container 3.
[0035] This ventilation device ensures bubble-free, uniform discharge of
the viscous material
from the application device I. When the outer casing 2 is compressed by a user
in the manner
described above, air located between the outer casing 2 and the inner
container 3 first escapes
through the annular gap between the neck region 6 of the outer casing 2 and
the insert 19 of the
inner container 3 and passes to the outside through the air-permeable threaded
connection between
the applicator 4 and the outer casing 2. Pressure on the outer casing 2 is
transmitted to the inner
casing 3, causing viscous material to be conveyed from the inner casing 3 into
the applicator 4 and
dispensed through its dispensing opening 5 onto a substrate. As soon as the
pressure on the outer
casing 2 is released, air is drawn in again from outside through the
connection region between the
applicator 4 and the outer casing 2 into the intermediate space between the
inner container 3 and
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the outer casing 2 in order to relieve the negative pressure built up here and
to return the outer casing
2 to its original shape. At the same time, however, no air enters the inner
container 3 storing the
viscous material, since this is sealed off from the intermediate space between
the outer casing 2 and
the inner container 3 by the sealing means 25 arranged on the applicator 4.
The outer casing 2 thus
resumes its original shape after each application procedure due to the inflow
of air, while the inner
container 3 is further compressed and irreversibly deformed with each
application procedure.
[0036] The integrated ventilation device prevents air from being drawn
into the inner container
3toring the viscous material during metering and subsequent resetting of the
outer casing 2 This
eliminates the need to shake or "spike" the application device 1 prior to use
and ensures an air
bubble-free application of the viscous material to a substrate. Since the
inner container 3 is further
deformed with each application procedure and this deformation is not
reversible, the viscous material
cannot run back into regions of the inner container 3 from which it would
first have to be moved back
towards the dispensing opening 18. Rather, the viscous material is always
immediately available in
any orientation of the application device 1 and can be dispensed reliably and
without bubbles. This
also achieves significantly improved residual emptying. The external
appearance of the application
device 1 is thereby consistently attractive to a user, since the outer casing
2 always returns to its
original shape, while the increasingly deformed inner container 3 is not
visible to the user.
[0037] Figure 10 shows an alternative embodiment of an applicator 4.
Compared to the
substantially rectangular shape of the applicator 4 in Figure 1, the
applicator 4 in Figure 10 is
designed in a delta shape. The outer edges 26, 27, 28, 29 of the applicators 4
of Figures 1 and 4
serve as means for smoothing the applied viscous material and as means for
cleaning adjacent
substrate regions, respectively. In this case, the main body 30 of the
applicator 4 is made of a more
rigid material than the means for smoothing and cleaning, which are made of a
pliable material.
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